Depending on what your search criteria is, you might end up with an album selected for playback as shown here:
(click to view)
Generally, most music tracks are 30 seconds in length but every now and then you can find full length material. The best part is that you don’t even have to be a member to use this.
LaLa, if you have not heard of it, is a CD trading service where you can list CDs that you have and CDs that you want. CD trades are one for one. Each CD that you trade from your have list will result in receiving a CD from your want list. All you do is pay for shipping and handling (roughly $1 per CD) and LaLa handles the rest. Learn about how it works or read a three part article by Ars Technica for more information.
I have been enjoying this service for some time now and discovered that opened up a store in addition to the trading service. Prices seem reasonable and it sounds like you can group CDs that you want to buy together in order to save on shipping and handling costs. Check it out:
…and in my want list, I see the option to buy the CDs that I want instead of waiting for the option to trade with some other user: